There have been known sample processing apparatuses such as blood cell analyzers, urine particle analyzers, blood coagulation measuring apparatuses, immune analyzers, biochemical analyzers, nucleic acid amplification detecting apparatuses, and smear preparing apparatuses. Such a sample processing apparatus includes an aspiration tube for aspirating a sample or a reagent. The sample processing apparatus is configured to locate this aspiration tube above a sample container or a reagent container, and then to lower the aspiration tube to insert the aspiration tube into the sample container or the reagent container, thereby to aspirate the sample or the reagent.
In production of such a sample processing apparatus, dimensional variation may occur in dimensions of parts to be used when the parts are produced, mounting dimensions when the parts are assembled, and the like. This makes it difficult to accurately locate the aspiration tube above a sample container or a reagent container. In such a sample processing apparatus, if the aspiration tube cannot be accurately located, there is a risk that the aspiration tube may collide with a sample container, a reagent container, the apparatus body, or the like, causing poor aspiration or damage of the aspiration tube.
Japanese Laid-Open Patent Publication No. H11-160326 discloses a dispenser that can adjust the position of a nozzle (aspiration tube). The dispenser disclosed in Japanese Laid-Open Patent Publication No. H11-160326 includes a tip attachment part to which a nozzle tip is detachably attached. Between this tip attachment part and a dispensing pump, a jamming detection part is provided. In the dispenser, a positioning detection member having an insertion hole formed therein is disposed. When the position of the nozzle is to be adjusted, the tip attachment part (nozzle) having the nozzle tip attached thereto is lowered from above the positioning detection member, and whether the nozzle has collided with the positioning detection member is detected by the jamming detection part. When the leading end of the nozzle has entered the insertion hole, the nozzle does not collide with the positioning detection member. When the leading end of the nozzle goes outside the insertion hole, the nozzle collides with the positioning detection member. Such detection of presence or absence of collision is performed at a plurality of points while the position in the horizontal direction is being shifted. Thus, the position in the horizontal direction of the nozzle is corrected.
However, in the dispenser disclosed in Japanese Laid-Open Patent Publication No. H11-160326, in order to adjust the position in the horizontal direction of the nozzle, the nozzle is caused to collide with the positioning detection member a plurality of times. Thus, there is a risk that the nozzle is deformed or damaged, or the nozzle tip comes off the tip attachment part.